New study shows abnormal brain structure in babies of marijuana-smoking women
A new study has demonstrated a link between smoking marijuana during pregnancy and abnormalities in an unborn child’s brain.
Experts warn that children exposed to marijuana in the womb were found to have a thicker prefrontal cortex region of the brain, when compared to children who were not exposed to the herb.
The prefrontal cortex is a region of the brain that is linked to memory, decision-making, complex cognition and personality.
While the current study combined with existing literature supports the importance of preventing the use of marijuana and cigarettes during pregnancy, the effect that marijuana has on brain morphology in offspring was unknown until now.
For the study, Dr Hanan El Marroun and her team at the Erasmus University Medical Centre in the Netherlands used MRI scans to examine the brains of 54 children between six and eight years old.
All the children had been exposed to cannabis while they were in the womb, while most had also been exposed to tobacco.
The researchers also examined brain scans of 96 children exposed to just tobacco in the womb, as well as a control group of 113 children with no exposure to either substance.
On comparing the brain scans of all three groups, the scientists noted differences in the prefrontal cortex, which was thicker in the children who had been exposed to marijuana.
These findings suggest that marijuana exposure has different effects than exposure to tobacco, according to the researchers.
Dr John Krystal, editor of Biological Psychiatry, the journal in which the new study was published, said: “The growing legalization, decriminalization, and medical prescription of cannabis increases the potential risk of prenatal exposure.
“This important study suggests that prenatal exposure to cannabis could have important effects on brain development.”
Dr El Marroun said: “This study is important because cannabis use during pregnancy is relatively common and we know very little about the potential consequences of cannabis exposure during pregnancy and brain development later in life.”
An estimated two to 13 percent of women across the world are believed to use the drug while they are pregnant.
Meanwhile, a study published earlier this month in the American Journal of Obstetrics and Gynaecology found that pregnant women who smoked both marijuana and tobacco were more than twice as likely as women who used neither substance to experience asthma; two-and-a-half times as likely to deliver prematurely, and nearly three times as likely to have babies with small heads or low birth weight.
Although smoking cigarettes alone was also linked to smaller infant head size, lower birth rate and premature delivery, these risks were higher when combined with marijuana.
Previous research has identified short and long-term behavioural consequences of prenatal cannabis exposure.